MX2009002089A

MX2009002089A - Abrasion-resistant hinge rods in modular plastic conveyor belts.

Info

Publication number: MX2009002089A
Application number: MX2009002089A
Authority: MX
Inventors: James O Gundlach
Original assignee: Laitram Llc
Priority date: 2006-08-30
Filing date: 2007-08-21
Publication date: 2009-03-09
Also published as: JP2010502534A; DK2064136T3; ES2403028T3; EP2064136A1; JP5323703B2; PL2064136T3; WO2008027752A1; CN101511711A; US20080067040A1; CA2661988A1; EP2064136B1; US7438179B2; BRPI0714524A2; CN101511711B

Abstract

A modular conveyor belt (10) formed by rows (12A.12B) of belt modules (14) connected at hinge joints by non-circular hinge rods (30). Each rod has an arcuate outer face that forms a portion of a cylinder and extends circumf erentially over a first angle. An axial groove (32) is formed in the hinge rod opposite its outer face. Openings in hinge eyes (20,21) at opposite ends of the belt rows are sector-shaped. The openings (20) along a leading end of a row are shaped to receive a hinge rod snugly. The openings (21) along a trailing end of an adjacent row have similar radial dimensions, but extend circumferentially over a greater second angle. The hinge eyes of adjacent rows are interleaved to receive a rod and give the hinge joint a range of articulation. Protrusions (28) extending into the openings are received in the grooves in the rod to register it in the joint with limited vertical motion.

Description

ARTICULATED RODS RESISTANT TO ABRASION IN MODULAR PLASTIC CONVEYOR BANDS BACKGROUND The invention relates generally to mechanically driven modular plastic conveyor belts and, more particularly to modular plastic conveyor belts interconnected in an articulated manner line by line by non-circular articulated cranks. Conventional modular conveyor belts and chains are constructed of modular connections or band modules arranged in a row. The separate articulated rings extending from each end of the modules include aligned openings. The rings articulated along one end of a row of modules are interspersed with the articulated rings of an adjacent row. The articulated rod, with bearings in the aligned openings of the intercalated articulated rings, connects the adjacent rows between them end to end to form an endless conveyor belt capable of articulating around a driving sprocket or drum. Because modular plastic conveyor belts do not corrode and clean easily, they are often used instead of metal strips. Commonly the connecting rods in the plastic bands They are also made of plastic. The articulated rods are typically circular in cross section and are housed in circular openings in the articulated rings. The relative movement between the articulated rods and the walls of the articulated rings as the band is articulated around the sprockets tends to wear out both the articulated rods and the wall of the articulated ring. In abrasive environments, such as the transport of potatoes and other agricultural products, this wear is accelerated by the intrusion of dirt and sand into the joints of the belt. The articulated metal connecting rods are sometimes used to increase the life of the connecting rods. But this does not end with the relative movement between the connecting rod and the wall of the articulated ring and the wear of the belt module in the joint is still a problem. Articulated non-circular tapes made of a flexible material have been proposed to resist wear. The articulated rings that form grooves with the widened ends allow the closed articulated belt to flex at a limited angle without rubbing frictionally with the articulated rings as the band articulates. Such an arrangement is effective to increase the life of use but the flexible articulated belt is inherently weak in shear strength and not suitable for transport heavy loads. The U.S. Patent No. 7,055,678 discloses a barrel-shaped connecting rod that is held loosely in the articulated rings along a row of the band. The openings in the interleaved hinged rings of the adjacent row are larger to allow the band to articulate in the joint between the adjacent rows. But the larger opening produces the play of the articulated rod which results in undesirable movement and friction of the rod against the walls of the larger openings. Thus, there is a need for a modular plastic conveyor belt that can withstand friction in the joint for a long operating life even in abrasive environments. SUMMARY This need and other needs are met by a modular plastic conveyor belt that incorporates the features of the invention. A version of the band comprises a series of rows of modules of the plastic band. Each row includes at least one web module that extends from the front end towards a rear end in the direction of travel of the web. Each row also includes a first set of articulated rings along its front end and a second set of articulated rings along its rear end. The first set of articulated rings has first openings formed in them, and the second set of articulated rings have second openings. The rows are arranged end to end with the first set of articulated rings of a row interspersed and aligned with the second set of articulated rings of an adjacent row. The band also comprises a plurality of articulated rods. Each articulated rod is a sectorial portion of a circular cylinder having a radius measured from the central axis. The sector portion subtends a first angle from the central axis. Each of the first openings has a shape similar to the cross section of the articulated rods with a slightly larger radius to receive an articulated rod with little clearance. Each of the second openings has the shape of a sector of a circle having a radius slightly larger than that of the articulated rod and subtending a second angle greater than the first angle. An articulated rod received in the first openings of the first set of articulated rings of a row and in the second openings of the second set of articulated rings of an adjacent row forms an articulated joint between the adjacent rows. A second version of a modular plastic conveyor belt also comprises a series of rows of Plastic band modules. Each row includes at least one web module that extends from the front end to the rear end in the direction of travel of the web. A first set of articulated rings is formed along the front end of each row, and a second set of articulated rings, along the rear end. The first articulated rings have first openings in them and the second articulated rings have second openings. The rows are arranged end to end with the first set of articulated rings of a row interspersed and aligned with the second set of articulated rings of an adjacent row. The first and second openings are generally formed in sectors. The first openings subtend a first angle from the vertex of the sector. The second openings subtend a second larger angle from the vertex of the sector. A plurality of articulating rods, each having a cross section generally formed in sectors similar in shape and size to the first openings, are received in the first and second aligned openings of the first and second articulated rings interspersed with adjacent rows to interconnect the rows in the joints articulated in a modular plastic conveyor belt. Each articulated rod defines an axis that is perpendicular to its cross section formed in sectors through the vertex - - of the cross section formed in sectors. Still another version of a band incorporating the features of the invention comprises a series of rows of plastic band modules. Each row includes at least one web module that extends from the front end to the rear end in the direction of travel of the web. Each row has a first set of hinged rings along the front end and a second set of rings hinged along the rear end. The first articulated rings have first openings therethrough and the second articulated rings have second openings. The rows are arranged end to end with the first set of articulated rings of a row interspersed and aligned with the second set of articulated rings of an adjacent row. The conveyor belt also comprises a plurality of articulated rods. Each articulated rod includes a convex outer surface, a first outer end surface and a second outer end surface. The convex outer end surface extends circumferentially through a first angle between a first edge and a second edge of the articulated rod and axially defining the length of the rod. The first outer end surface extends radially inwardly from the outer surface - - curve at the first edge, and the second outer end surface extends radially inwardly from the curved outer surface at the second edge. A groove is formed in the articulated rod opposite the convex outer surface. The groove extends axially along the articulated rod between the first and second outer end surfaces. Each of the first openings has a shape similar to the cross section of the connecting rods to receive an articulated rod with a little play. Each of the second openings subtends a second angle greater than the first angle. An articulated rod received in the first openings of the first set of articulated rings of a row and in the second openings of the second set of articulated rings of an adjacent row connects adjacent rows together in an articulated joint. Each of the articulated rings has a protrusion in the opening received in the groove in the articulated rod to match the articulated rod in the first and second openings. Another version of a modular plastic conveyor belt comprises a series of rows of one or more plastic band modules. Each row extends from the leading end to the trailing end in the direction of travel of the band and includes a first set of articulated rings along the leading end and a - - second set of rings articulated along the rear end. The first set of articulated rings each has first openings, and the second set of articulated rings each has second openings. The rows are arranged end to end with the first set of articulated rings of a row interspersed and aligned with the second set of articulated rings of an adjacent row. The conveyor belt further comprises a plurality of articulated rods. Each articulated rod includes a curved outer surface, a first flat outer surface and a second flat outer surface. The curved outer surface forms a portion of a cylinder. It extends circumferentially through a first angle between a first edge and a second edge of the articulated rod and defines axially the length of the articulated rod. The first flat outer surface extends radially inwardly from the curved outer surface at the first edge, and the second flat outer surface extends radially inwardly from the curved outer surface at the second edge. Each of the first openings has a shape similar to the cross section of the articulated rods with slightly larger dimensions to receive an articulated rod with a bit of clearance. Each of the second openings has radial dimensions slightly larger than the connecting rod - - articulated and subtending a second angle greater than the first angle so that an articulated rod received in the first openings of the first set of articulated rings of a row and in the second openings of the second set of articulated rings of an adjacent row form with the rings articulated joint articulated between the adjacent rows. Another aspect of the invention provides an articulated connecting rod for interconnecting the adjacent rows of a conveyor belt through the articulated rings aligned to form a joint between the adjacent rows. The articulated rod comprises a curved outer surface forming a portion of a cylinder. The articulated rod extends circumferentially through a first angle and axially defines the length of the articulated rod. A groove is formed in the connecting rod hinged radially inwardly of the curved outer surface. The groove extends axially along the articulated rod. BRIEF DESCRIPTION OF THE DRAWINGS These features and aspects of the invention, as well as its advantages, are better understood by reference to the following description, appended claims and accompanying drawings in which: Figure 1 is an exploded isometric view of a portion of a modular plastic conveyor belt incorporating the features of the invention, including an articulated rod resistant to abrasion; Figure 2 is a front view of the articulated rod of Figure 1; Figure 3 is an isometric view of the articulated rod of Figure 1 showing how its shape is formed; Figure 4 is a side elevational view of a portion of the conveyor belt of Figure 1 in articulation. DETAILED DESCRIPTION A portion of a modular plastic conveyor belt incorporating the features of the invention is shown in Figure 1. The band 10 is constructed of a series of rows 12A, 12B of one or more band modules 14. Each row extends from the front end 16 to the rear end 17 in the direction of travel of the band 18. A first set of articulated rings 20 are disposed along the front end of each strip row; a second set 21 is arranged along the rear end. The first openings 22 are formed in the first articulated rings, and the second larger openings 23 are formed in the second articulated rings. The first and second openings are each limited by a curved wall 24, 24 'and a pair of end walls 26, 27 to define an opening generally formed in sectors. A protrusion 28 forms a flange extending towards the openings between the two end walls. An articulated rod 30 received in the first openings 22 of the first articulated rings 20 of a rear row 12B and in the second openings 23 of the second articulated rings 21 interleaved and aligned of the front row 12A, connects the adjacent rows together in an articulated joint. The cross section of the articulated rod is geometrically similar to the cross section of the first openings in the first articulated rings. The dimensions of the first openings and the radial dimensions of the second openings are slightly larger than the cross section of the articulated rod to allow easy insertion of the articulated rod into the articulated joint. There is a small gap so that the connecting rod in the first openings minimizes the friction between the connecting rod and the walls of the first openings during the operation of the band. A groove 32 formed axially along the articulated rod receives the protrusions in the first and second openings to match the rod in place within the aligned openings and to limit the amount of clearance in the second openings and, consequently the friction between the connecting rod and the walls of the ring, which can accelerate wear, especially in an abrasive environment The shape of a preferred version of the articulated rod is shown in Figures 2 and 3. The articulated rod 30 has a convex curved outer surface 34, which is a portion of the outer surface 36 of a circular cylinder. Two halves of imaginary planes 38, 39 intersecting the cylinder on its axis 40 define a first angle a, which is preferably between 90 ° and 180 °. The curved outer surface extends circumferentially through the first angle. The first and second flat end surfaces 42, 43 are in the two halves of the planes and intersect the outer surface 34 at the first and second edges 44, 45. The slot of the articulated rod (32 in Figure 2, but not shown in Figure 3) extends axially along the opposite rod to its curved outer surface 34. Thus, in the cross section perpendicular to its longitudinal axis, the articulated rod is generally formed in sectors, limited by a circular arc 34, a pair of linear segments 42, 43 extending radially inwardly of the circular arc towards a vertex located on the longitudinal axis 40, and the perimeter of an axial slot 32 disposed along the axis between the arcs two linear segments. The articulated rod is preferably made from a plastic material such as polypropylene, polyethylene or nylon. It can be extruded or molded. The slot can be formed in the extrusion or molding process or machined in a secondary manufacturing stage. The web modules are preferably modular plastic modules molded from thermoplastic polymers, such as polyethylene, polypropylene, acetal or composite polymers, in an injection molding process. The articulation of a portion of a conveyor belt for example around a sprocket is shown in Figure 4. Two articulated joints 46 are shown in articulation; another articulated joint 47 is shown without articulation. The first openings 22 in the articulated rings 20 subtend a first angle a from the vertex 40 of the opening formed in sectors. The second openings 23 in the second articulated rings 21 subtend a second angle ß from the vertex. The first angle a as shown, is between 90 ° and 180 °. The second angle ß as shown is greater than 180 °. Consequently, when the openings in the interleaved hinged rings are aligned in an articulated joint 47 without articulation, the articulated rod 30 closed in the first smaller openings 22 are generally centered within the first larger openings with unfilled spaces 48, 49 and greater. inferiors available for - - joint. The protrusions 28 received in the slot 32 of the articulated rod make the articulated rod coincide in position and limit the vertical clearance of the connecting rod in the openings, especially in the second larger openings, minimizing friction between the connecting rod and the walls of the rings. articulated. In an articulated joint 46, the front row 12A rotates around the articulated rod 20, which rises towards the upper space 48 of the second openings 23. Of course, although the upper space decreases due to the presence of the articulated rod , the lower space increases correspondingly. When the band is folded in the reverse direction, the articulated rod inverse fills the lower space and opens the upper space as the band articulates in the joint articulated in the opposite direction. Although the invention has been described in detail with respect to a preferred version, other versions are possible. For example, the angular extension of the articulated rods and the smaller openings, which were shown as being between 90 ° and 180 °, may be less than 90 ° or greater than 180 ° in certain applications. The angular extent of the second larger openings may be less than 180 ° if the articulation range needs to be limited. As another example, the first and second openings can be disposed of such that observed in an articulated joint without articulation, the rod jointed in the first openings does not center with respect to the second larger openings, to allow for example, a greater degree of articulation than folding in the reverse direction or completely eliminating the folding in the opposite direction. Still as another example the curved walls limiting the first openings were shown oriented closer to the end of the row of the strip than the protrusions and the curved walls which limit the second openings were shown farther away from the end of the row of the band. than the protrusions. The orientations of the first and second openings can both be reversed without affecting the ability of the band to articulate. Thus, as these few examples are suggested, the scope of the claims should not be limited to the preferred version described in detail.

Claims

CLAIMS 1. A modular plastic conveyor belt comprising: a series of rows of plastic strip modules wherein each row includes at least one web module extending from the front end to the rear end in the travel direction of the band and includes a first set of articulated rings along the leading end and a second set of articulated rings along the trailing end, wherein the first set of articulated rings has first openings through it and wherein the second set of articulated rings have second openings therethrough, the rows being arranged end to end with the first set of articulated rings of a row interleaved and aligned with the second set of articulated rings of an adjacent row; a plurality of articulated rods, wherein each articulated rod is a sectorial portion of a circular cylinder having a radius measured from the central axis and the sector portion subtends a first angle from the central axis; wherein each of the first openings has a shape similar to the cross section of the connecting rods with a slightly larger radius to receive a articulated rod with little clearance and wherein each of the second openings has the shape of a sector of a circle that has a radius slightly greater than that of the articulated rod and subtends a second angle greater than the first angle so that a articulated rod received in the first openings of the first set of articulated rings of a row and in the second openings of the second set of articulated rings of an adjacent row form an articulated joint between the adjacent rows.
2. A modular plastic conveyor belt as in claim 1, wherein each articulated rod further includes a slot extending along the central axis and wherein each of the first and second articulated rings has a protrusion extending to the first and second openings and is received in the slot of the articulated connecting rod received.
3. A modular plastic conveyor belt as in claim 1 or 2, wherein the first angle is between 90 ° and 180 °.
4. A modular plastic conveyor belt as in claim 1 or 2, wherein the second angle is greater than 180 °.
5. An articulated connecting rod to connect the adjacent rows of a conveyor belt together through aligned articulated rings forming a joint between adjacent rows comprising the articulated rod: a curved outer surface forming a portion of a cylinder and extending circumferentially through a first angle and axially to define the length of the articulated rod; and a groove disposed radially inwardly of the curved outer surface and extending axially along the articulated rod and circumferentially through the first angle.
6. A modular plastic conveyor belt comprising: a series of rows of plastic strip modules wherein each row includes at least one web module extending from the front end to the rear end in the direction of travel of the web; band and includes a first set of articulated rings along the front end and a second set of rings hinged along the rear end, wherein the first set of articulated rings has first openings therethrough and wherein the second set of articulated rings has second openings therethrough, the rows being arranged end to end with the first set of articulated rings of a row interleaved and aligned with the second set of articulated rings of an adjacent row; where the first openings are generally formed in sectors and subtend a first angle from the vertex of the sector; wherein the second openings are generally formed in sectors and subtend a second angle from the vertex of the sector, wherein the second angle is greater than the first angle; a plurality of articulated rods, each having a cross section generally formed in sectors, similar in shape and size to the first openings and defining an axis perpendicular to the cross section generally formed in sectors through the apex of the cross section formed in sectors, received in the first and second aligned openings of the first and second articulated rings interspersed with adjacent rows to interconnect the rows in the articulated joints in a modular plastic conveyor belt.
A modular plastic conveyor belt as in claim 6, wherein each articulated rod further includes a slot extending along the axis and wherein each of the first and second articulated rings has a protrusion extending to the first and second openings and is received in the slot of the articulated connecting rod received.
8. A modular plastic conveyor belt as in claim 6 or 7, wherein the first angle is between 90 ° and 180 °.
A modular plastic conveyor belt as in claim 6 or 7, wherein the second angle is greater than 1800.
10. A modular plastic conveyor belt comprising: a series of rows of plastic band modules wherein each The row includes at least one belt module extending from the front end to the rear end in the direction of travel of the belt and includes a first set of rings articulated along the front end and a second set of rings hinged at the front. length of the rear end, wherein the first set of articulated rings has first openings therethrough and wherein the second set of articulated rings has second openings therethrough, the rows being arranged end to end with the first set of rings articulated from a row interspersed and aligned with the second set of articulated rings of an adjacent row; a plurality of articulated rods, wherein each articulated rod includes: a convex outer surface extending circumferentially through a first angle between a first edge and a second edge of the connecting rod articulated and axially to define the length of the connecting rod; a first outer end surface extending radially inwardly from the curved outer surface at the first edge; and a second outer end surface extending radially inward from the curved outer surface at the second edge; a groove opposite the convex outer surface extending axially along the articulated rod between the first and second outer end surfaces; wherein each of the first openings has a shape similar to the cross section of the connecting rods for receiving an articulated rod with little clearance and wherein each of the second openings subtend a second angle greater than the first angle so that a articulated rod received in the first openings of the first set of articulated rings of a row and in the second openings of the second set of articulated rings of an adjacent row connect adjacent rows together in an articulated joint; and wherein each of the articulated rings has a protrusion in the opening received in the slot in the articulated connecting rod received to match the connecting rod articulated in the first and second openings.
11. A modular plastic conveyor belt as in claim 10, wherein the first angle is between 90 ° and 180 °.
12. A modular plastic conveyor belt as in claim 10, wherein the second angle is greater than 180 °.
13. A modular plastic conveyor belt comprising: a series of rows of plastic band modules wherein each row includes at least one belt module extending from the front end to the rear end in the direction of travel of the band and includes a first set of articulated rings along the front end and a second set of rings hinged along the rear end, wherein the first set of articulated rings has first openings therethrough and wherein the second set of articulated rings has second openings therethrough, the rows being arranged end to end with the first set of articulated rings of a row interleaved and aligned with the second set of articulated rings of an adjacent row; a plurality of articulated rods, wherein each articulated rod includes: a curved outer surface forming a portion of a cylinder and extending circumferentially through a first angle between a first edge and a second edge of the connecting rod and axially to define the length of the connecting rod; a first flat outer surface extending radially inward from the curved outer surface at the first edge; and a second flat outer surface extending radially inward from the curved outer surface at the second edge; wherein each of the first openings has a shape similar to the cross section of the articulated rods with slightly larger dimensions to receive an articulated rod with little clearance and wherein each of the second openings have radial dimensions slightly larger than the articulated rod and subtend a second angle greater than the first angle so that an articulated rod received in the first openings of the first set of articulated rings of a row and in the second openings of the second set of articulated rings of an adjacent row form with the articulated rings an articulated joint between the adjacent rows.
14. A modular plastic conveyor belt as in claim 13, wherein the first angle is find between 90 ° and 180 °.
15. A modular plastic conveyor belt as in claim 13, wherein the second angle is greater than 180 °. A modular plastic conveyor belt as in claim 13, 14 or 15, wherein the articulated rod further includes a slot opposite the curved outer surface extending axially along the articulated rod between the first and second flat outer surfaces. and wherein each of the first and second articulated rings has a protrusion that extends into the first and second apertures and is received in the slot of the articulated connecting rod received.